Glass cages is the cheapest, but also they are the cheapest. Then there is Miracles in glass and Aquarium Obsessed, but Miracles wanted well over $1000 for my 48x30x24"h starphire tank. So I built it myself for about $600... eurobrace, starphire, and all. The local glass shop is a distributor for starphire though, so the price was pretty low compared to most.
If you use starphire, just be sure to pick up a short-wave UV lamp to make sure the tin sides face out.